1. Field of the Invention
The present invention relates to air treatment systems, and more specifically to air treatment systems for mobile applications.
2. Description of the Related Art
The need for effective filtration of an enclosed operator space is especially important in the agricultural field where the operator of a tractor or other vehicle is traversing an environment laden with many different types of particles, aerosols and vapors. In the past, the EU requirement for filtration of an operator space has been met with a category 2 filter (CAT 2 filter) that filters larger particles as fine as dust. Newer EU standards require a category 4 filter (CAT 4 filter) which not only filters out dust but in addition aerosols and vapors.
This requirement is especially important for operating conditions in which a field is treated with insecticide or herbicides. There are CAT 4 filters that are available for this purpose but they are expensive and have a sensitivity to harsh ambient conditions that limits their effective service life. As a result, the use of a CAT 4 filter is done on a selected basis so that it is used only when aerosols and vapors may be present in the ambient environment. The current systems for adding the CAT 4 filter are involved and introduce an added level of complexity that increases cost and the continuing maintenance requirement.
Accordingly, what is needed in the art is a simplified, yet reliable, air treatment system to provide selective filtration levels for an operator enclosure.